Barometric draft regulator and burner control



June 29, 1954 E. A. FIELD 2,682,299

BAROMETRIC DRAFT REGULATOR AND BURNER CONTROL Filed July 21, 1951INVENTOIg. fawa/d /9, 56/0 @m ewe Patented June 29, 1954 UNITED STATEfii ATENT OFFICE BAROMETRIC DRAFT REGULATOR AND BURNER CONTROL Claims. 1

This invention relates to improvements in barometric draft regulatorsand burner controls.

The main objects of this invention are:

First, to provide a barometric draft regulator for gas fired boilers andfurnaces which is effective in controlling the updraft and alsoconstitutes a venting-means in the case of downdrafts or backdrafts.

' Second, to provide a structure of this character which acts in theevent of downdraft, internal pressure, or excessive pressure in the fineto 'close the. valve in the gas supply to the burner gate acting todirect the flow of gases against 1 the thermal switch element.

Fourth, to provide a structure having these advantages which is adaptedfor use both on horizontal and vertical flues.

Objects relating to details and economies of the invention will appearfrom the description to follow.

"The invention is pointed out in the claims.

A. preferred embodiment of the invention is illustrated in theaccompanying drawings, in which:

Fig. 1 is a fragmentary view of a draft regulator embodying my inventionpartially in section on a line corresponding to the broken line l-| ofFig. 2. A wiring diagram is shown of the main control parts, therelationship of the control and the gas valve, which is shownconventionally as a solenoid valve, being illustrated.

Fig. 2 is a front elevational View illustrating the regulator asinstalled on a horizontal line.

1 Fig. 3 is a fragmentary perspective View partiall3 in section on aline corresponding to line 3- 3 of Fig. 2 illustrating details of thehousing structure and the gate mounting.

Fig. 4 is a fragmentary view on a line corresponding to line ill-4 ofFig. 1.

The present invention relates to an automatic draft regulator and burnercontrol which is suitable for use in connection with commercial andindustrial gas fired boilers and furnaces. Since a gas burner can beextinguished easily by a downdraft it is important, unless the burnerhas a forced draft, that means he provided for bypassing the downdraftflow from the burner and thereby prevent or minimize the likelihood ofthe flame being extinguished or resulting in such combustion conditionsthat the dangerous creation and escape of monoxide or other dangerousgas is prevented.

In the embodiment of the invention illustrated, i represents ahorizontal smoke flue and 2 a gate housing whichis secured to and opensinto the flue, the details of-mounting not being illustrated. Thehousing includes an annular gate support member 3 which is positioned atthe front of the housing and is provided with vertical rearwardlyprojecting wing-like side plates 5 having outturned flanges 6 at theirforward ends. The gate 7 is shaped to swing between these side platesand has a forwardly inclined segmentalfiange-like top portion 6.

The pivot members is' fixedly secured to the front sideof the gate belowthe vertical center thereof. This pivotmernber 9 has pivot portions Itat its ends'provided with knife-like pivot edges I I. The side plates5'have elongated horizontal openings l2 therein through which thesepivot portions project.

V shaped. plate-likebearing members l3 are disposed facing'upwardly andresting upon the bottom edges [4 of the slots of the plates 5. Thebearing members have slots or notches It in their ends, the notches inthe front ends of the bearing'members receiving the front edges It ofthe slots 12 and the notches in their rear edges being engaged bybearing retaining plates ll. The edges 16 are notched at 18 while thebearing retaining plates I! have notches M in their bearing memberengaging edges. The slots or notches in the bearing members are of suchtransverse dimensions as to permit tilting of the bearing members ontheir support and thus permitting'them toalign-With the pivot edges H ofthe-pivots 1B.

The gate is provided with an adjustable platelike weight 20 whichismounted on the screw 2i for swinging adjustment in a plane parallel tothe plane of the gate. The weight 23 is 'clampedtuponathe front sideof.the gate below the pivot thereof' while the weight 24 is adjustablysupported on ;the rear side of the gate by having threadedengagement'with the bolt 25, the forward end ofwhich' clamps the weight23 to the gate.

Toa-djust the gate to the desired draft it is provided withcav forwardlyprojecting arm 26 which is securedthereto above the pivot and adjacentone side edge to project a substantial distance. This arm has adownturned portion Ell with spaced holes 28 and 29 therein. A pluralityof washer-like auxiliary weights are provided to permit adjustment ofthe gate to provide the desired closing torque or to adjust the gate tothe desired draft. These weights are in the embodiment illustratedthreaded upon a holder 3! having an eye 32 at its upper end connected bythe chain 33 to the link 34 which is selectively engageable with theholes 28 and 29.

When the regulator is installed on a horizontal flue, as illustrated,the link 34 should be engaged with the hole 29. These holes have beenspaced to generally compensate for the difference in draft conditionscommonly found in horizontal and vertical flues. When the gate swingsoutwardly as the result of a downdraft as indicated by the dotted linesin Fig. l, the auxiliary weight is supported by the chain 35 which isconnected to the eye 32 of the holder 3| and to the bracket 36projecting from the housing. The weights 20, 23 and 24 constituteweighting means for the gate and are so disposed relative to the gate,when the gate is in a closed position, that the center of gravity of thegate and said weighting means thereon is disposed vertically below thepivotal axis of the gate, so that when the gate is opened inwardly dueto an updraft or indraft the gate automatically returns to a closedposition after such updraft, and so that when the gate is openedoutwardly due to a downdraft or outdraft the gate automatically returnsto a I" closed position after such downdraft. The weight 30 supported bythe chain 33 and the arm 26 on the gate, as heretofore described,produces additional closing on the gate when the gate moves inwardly dueto an indraft, but when the gate moves outwardly due to an outdraft theweight 30 is supported by the chain 35 and bracket 36 on the housing asheretofore described. Also when there is neither an indraft nor anoutdraft the weight 30 is supported by the chain 35 and bracket 30 onthe gate housing; otherwise the weight 30 would open the gate outwardlyfrom a closed position when there was neither an indraft nor anoutdraft. The arrangement is such that the closing torque on 1? the gateis greater when the gate is moved inwardly due to indraft than whenmoved outwardly due to an outdraft, and the gate is in a closed positionwhen there is neither an indraft nor an outdraft.

In the diagrammatic portion of Fig. 1, 3! represents a burner controlvalve of the solenoid type. The thermal switch 38 is connected to asuitable current source indicated at 39. The switch is connected by theline 40 to the burner control valve 4! which is shown conventionally,this being a solenoid type valve, details of which are not illustrated.The connection 42 indicates the second connection for the switch to thevalve. A signal 43 may be connected in series in the line 40 if desired.The switch 38 is, in the embodiment illustrated, mounted on the outletbox 45 which is supported on the bracket 44 on top of the housing member3 so that the switch 38 is supported in a plane adjacent and above thepath of the upper edge of the gate and is supported between the outerend of the housing and the general plane extended of the upper draftcontrol portion of the gate when said portion is opened outwardly due toan outdraft, as shown in Fig. 1. When the gate swings outwardly as theresult of an outdraft, the escaping gases are, when the switch 38 ismounted as illustrated, directed by the gate against the thermal switch.

4 If the gases are heated the switch will be actuated.

The time of the actuation of the switch depends, of course, upon thetemperature of the gases but ordinarily there is sufficient heat in thegases to actuate the switch in a matter of seconds. Usually downdraftsor backdrafts are of short duration and as the gate swings to closedposition the thermal switch quickly cools, again opening the valve if itis the automatic type as indicated. However, it will be understood thata switch may be used that requires manual resetting. If the automaticopening type thermal switch is employed the opening and closing of thevalve is controlled by the thermal switch and no manual resetting of theapparatus is required. A slight outdraft will not actuate the thermalswitch as the hot gases must impinge or act on the switch for at least anumber of seconds before the switch will be actuated. Therefore theswitch constitutes a time delay element in the system. In the eventthere is an outdraft when the burner is not in operation, the switchwill not be actuated since the outdraft gases will be relatively cool.

I have illustrated and described my invention in an embodiment thereofwhich has proven to be very satisfactory and to accomplish the purposefor which it is desired. I have not attempted to illustrate or describeother modifications in the signal connections, the use of valvesrequiring manual resetting and the like, as it is believed that thisdisclosure will enable those skilled in the art to adapt my invention asmay be desired.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a barometric draft regulator and burner control, an open endedgate housing, a control gate disposed in said housing adjacent to theopen end thereof and pivotally mounted to swing about an approximatelyhorizontal axis, and having an upper draft control portion above saidaxis opening inwardly during an indraft and outwardly beyond the outerend of the housing during an outdraft, said gate being disposedapproximately vertical when closed, weighting means on said gate, thecenter of gravity of the gate and weighting means thereon being disposedvertically below the pivotal axis of the gate to effect a closing torqueon the gate, an arm mounted on said gate above its pivotal axis andprojecting outwardly therefrom, said arm having a downwardly projectingouter portion with vertically spaced holes therein, a bracket projectingforwardly from said housing, an auxiliary weight for producingadditional closing torque on the gate when the gate opens inwardly dueto an indraft, a first weight supporting element connecting saidauxiliary weight to said arm and selectively engageable with said holestherein, a flexible second supporting element connected to saidauxiliary weight and to said bracket and of such length as to supportthe auxiliary weight when the gate opens outwardly during an outdraft,and burner valve control means comprising a thermal switch, anelectrically controllable fuel supply valve and an electric circuithaving therein said thermal switch and said electrically controllablefuel supply valve, said thermal switch being disposed adjacent to theouter end of said housing and adjacent to and outwardly of the path ofmovement of said upper draft control portion of the gate and between theouter end r of the housing" and the general-planeextended of said upperdraft "control portion "when said upper draft control portionis openedoutwardly beyond'the outer end'of the housing'durlng an outdr'aft,whereby the heated gases from the housing during an 'outdraft' are"directed onto 'the thermal switch to* actuate the same to controlsupported by said second supporting-element from the bracket on thehousing.

means on said gate disposed to effect a closing torque on the gate, anarm mounted on said gate above its pivotal axis and projecting outwardlytherefrom, a bracket projecting forwardly from said housing, anauxiliary weight for producing additional closing torque on the gatewhen the gate opens inwardly due to an indraft, a first weightsupporting element connecting said auxiliary weight to said arm, aflexible second supporting element connected to said auxiliary weightand to said bracket and of such length as to support the auxiliaryweight when the gate opens outwardly due to an outdraft, and burnervalve control means comprising a thermal switch, an electricallycontrollable fuel supply valve and a circuit having therein said thermalswitch and said electrically controllable fuel supply valve, saidthermal switch being disposed adjacent to the outer end of the housingand adjacent to and outwardly of the path of movement of said upperdraft control portion of the gate and between the outer end of thehousing and the general plane extended of said upper draft controlportion when said upper draft control portion is opened outwardly beyondthe outer end of the housing during an outdraft; whereby the heatedgases from the housing due to an outdraft are directed onto the thermalswitch to actuate the same to control said circuit to actuate saidelectrically controllable fuel supply valve to shut off the supply offuel to a burner, said thermal switch operating through said circuit toclose said valve when the thermal switch is heated by the gases from thehousing and when said auxiliary weight is being supported by said secondsupporting element from the bracket on the housing.

3. In a barometric draft regulator and burner control, an open endedgate housing, a control gate disposed in said housing adjacent to theopen end thereof and pivotally mounted to swing,

about an approximately horizontal axis, and hav ing an upper draftcontrol portion above said axis opening inwardly during an indraft andoutwardly beyond the outer end of the housing during an outdraft, saidgate being disposed approximately vertical when closed and disposed forits upper portion to swing inwardly and outwardly of the housing,weighting means on said gate disposed to effect a closing torque on thegate, an arm mounted on said gate above its pivotal axis-and projectingoutwardly therefrom; a

bracketprojecti-ng' forwardly fromsaid housing,

an auxiliary'weight for producing additional closingtorque on-the gatewhen the gate opens inwardly' dueto an'indraft, a first'weightsupporting elementconnecting-said auxiliary weight to said arm, afiexible-second supporting element connectedto said auxiliary weight andto said bra cket and or suchlength as tosupport the auxiliaryweightwhen-the gate opens outwardly "due to' an o'utdraft, and burner valvecontrol means comprising a thermal switch, an electricallycontrollablefuel supply valve and a-circuit having therein said thermalswitch and said electrically controllable fuel supply valve, saidthermal switch being disposed adjacent to the outer-end of the housingand adjacent to and outw'ai'dly of thepath of movement of said upperdraft control portion of the gate and between the outer end of thehousing and the general plane extended of said upper draft controlportion when said upper draft control portion is opened outwardly beyondthe outer end of the housing during an outdraft; whereby the heatedgases from the housing due to an outdraft are directed onto the thermalswitch to actuate the same to control said circuit to actuate saidelectrically controllable fuel supply valve to shut off the supply offuel to a burner, said thermal switch operating through said circuit toclose said valve when the thermal switch is heated by the gases from thehousing and when said auxiliary weight is being supported by said secondsupporting element from the bracket on the housing, the gate having anoutwardly inclined segmental flangelike top portion facilitating thedirecting of the outdraft gases upon the switch.

4. In a barometric draft regulator and burner control, an open endedgate housing, a pivotally mounted control gate disposed in said housingand having a draft control portion on one side of the pivotal axis ofthe gate disposed adjacent to the outer end of the housing for openinginwardly during an indraft and outwardly beyond the outer end of thehousing during an outdraft,

weighting means on said gate acting to effect a closing torque thereon,an auxiliary Weight for producing additional closing torque on the gatewhen the draft control portion of the gate opens inwardly due to anindraft, means for supporting said auxiliary weight from said housingwhen the gate opens outwardly, and burner control means comprising athermal switch, an electrically controllable fuel supply valve and acircuit having therein said thermal switch and said electricallycontrollable fuel supply valve, said thermal switch being disposedadjacent to the outer end of the housing and adjacent to and outwardlyof the path of movement of said draft control portion of the gate andbetween the outer end of the housing and the general plane extended ofsaid draft control portion when the draft control ortion is openedoutwardly beyond the outer end of the housing during an outdraft wherebythe heated gases from the housing due to an outdraft are directed ontothe thermal switch to actuate the same to control said circuit toactuate said electrically controllable fuel supply valve to shut off thesupply of fuel to a burner, said thermal switch operating through saidcircuit to close said valve when the thermal switch is heated by saidgases from the housing and when said auxiliary weight is being supportedby said supporting means from the housing.

5. In a barometric draft regulator and burner control, a gate housing, apivotally mounted control gate disposed in said housing and having adraft control portion on one side of the pivotal axis of the gatedisposed adjacent to the outer end of the housing for opening inwardlyduring an indraft and outwardly beyond the outer end of the housingduring an outdraft, weighting means on said gate acting to effect aclosing torque thereon when opening inwardly during an indraft and whenopening outwardly beyond the outer end of the housing during anoutdraft,

and burner control means comprising a thermal switch, an electricallycontrollable fuel supply valve and a circuit having therein said thermalswitch and said electrically controllable fuel supply valve, saidthermal switch being disposed adjacent to the outer end of the housingand adjacent to and outwardly of the path of movement of said draftcontrol portion of the gate and between the outer end of the housing andthe general plane extended of said draft control portion when said draftcontrol portion is opened outwardly beyond the outer end of the housingduring an outdraft whereby the heated gases from the housing during anoutdraft are directed onto the thermal switch to actuate the same tocontrol said circuit to actuate said electrically operable fuel supplyvalve to shut off the supply of fuel to a burner.

References Cited in the file of this patent UNITED STATES PATENTS WalkerAug. 13, 1946

